Interleukin-2 receptor alpha-chain expression in patients with alopecia areata.

Interleukin-2 (IL-2) is a lymphokine produced by activated T-cells. Its receptor, IL-2R, is expressed on T-cells. Several clinical and experimental findings point towards IL-2 as a crucial mediator inducing immunologic reaction against human follicle in alopecia areata. The objective of our study was to analyze the expression of IL-2R as a sign of T-cell activation in scalp biopsies of patients suffering from alopecia areata. An immunohistochemical analysis was used to determine the difference in cytokine-regulated expression of IL-2R between 45 patients with active and stable phase of alopecia areata and 23 healthy control subjects. In the patients with alopecia areata in active phase, the expression of IL-2R in scalp biopsies was significantly stronger than that in the patients with stable disease and in controls. The increase of IL-2R+ cells in early phase of the disease could suggest that T-lymphocyte activation with IL-2 secretion and IL-2R expression may initiate the immune inflammatory mechanism of alopecia areata.